The effect of free glycerol intake on cerebral glycerol concentration.

OBJECTIVE: Cerebral microdialysis (CMD) is a method used to measure the concentration of metabolites and glycerol in the interstitium of the brain. The aim of this study was to investigate the effect of parenterally applied medication and nutrition containing external free glycerol (EFG) on cerebral values of glycerol in patients monitored and treated for non-traumatic subarachnoid hemorrhage (SAH). METHODS: In 13 patients, the values of CG concentrations were measured using CMD. The amounts of parenterally applied EFG (in hourly intervals) were calculated from patient records. All data were gathered retrospectively. To analyze the association between the parameters of interest and their relationship, Spearman´s correlation and p-values were calculated. RESULTS: There was no evident relationship between the CG and EFG concentrations when the dataset was analyzed as a whole (r = -0.146). However, when the analysis was applied to single patients, a varying degree of correlations was discovered in 7 patients (r = 0.431-0.867). CONCLUSION: The possible effect of externally administered glycerol contained in pharmaceuticals and nutrition on its brain concentrations must be considered when interpreting data of CMD (Tab. 2, Fig. 4,Ref. 16) Keywords: glycerol, microdialysis, brain, subarachnoid hemorrhage.

Correction to: Multidisciplinary approach in the treatment of spinal dural arteriovenous fistula-results of endovascular and surgical treatment.

The author J. Adamkov was incorrectly captured in the original article and is now corrected in this article.

Multidisciplinary approach in the treatment of spinal dural arteriovenous fistula-results of endovascular and surgical treatment.

BACKGROUND: The results of treatment for spinal dural arteriovenous fistula (SDAVF) have been controversial. The goal of this study was to compare results of endovascular and surgical treatments to contribute to determining an optimal treatment strategy. METHODS: A retrospective analysis of the set of 24 SDAVF patients (11 in the endovascular and 13 in the surgical group) was performed. The clinical effect (using the modified Rankin scale [mRS]), the radicality, and the number of clinical recurrences as well as the impact of age, the level of impairment, and the duration of symptoms before the treatment were evaluated. RESULTS: The average age was 60.1 ± 8.4 years. The median duration of symptoms before establishing a diagnosis was 12 (1-70) months. Clinical improvement was reported in 11 out of 24 (45.8%) patients (36.4% following embolization and 53.8% following surgery, p = 0.444). Radical performance was achieved in 47.4% of endovascular versus 92.9% of surgical procedures (p = 0.009). Clinical recurrence was reported in 35.3% of patients in the endovascular group, whereas no clinical recurrence was reported in the surgical group (p = 0.0133). The graphical residuum after 1 surgery out of 14 (7.1%) was cured early during the control angiography. Clinical improvement was reported 42.1% of patients with mRS ≤ 3 versus 60% of patients with mRS ≥ 4 and, in 57.1% of patients aged ≥ 60 versus in 30% of patients < 60 years (p > 0.05 in both cases). The impact of the duration of symptoms on the clinical results was not statistically significant. CONCLUSIONS: The surgical treatment of SDAVF appeared to be a more efficient method in terms of the clinical effect, radicality, and lower recurrence rate in comparison with the endovascular treatment. No statistically significant dependence of the clinical result on age, deficit burden, or symptom duration was found.

The relationship between intracranial pressure and lactate/pyruvate ratio in patients with subarachnoid haemorrhage.

AIM: The aim of this study was to analyse the relationship between intracranial pressure (intracranial pressure monitoring) and lactate pyruvate ratio (cerebral microdialysis) in patients with ruptured intracranial aneurysms. METHODS: In a group of fifteen patients, intracranial pressure and lactate/pyruvate ratios were measured and logged in hourly intervals. The relationship between these two variables was subsequently analysed in two ways. 1) Intracranial hypertension (ICP > 20 mmHg) in the presence of energy deprivation (L/P ratio > 30) was noted. 2) The dynamics of L/P ratio changes in relation to immediate ICP and CPP values was analysed. RESULTS: Out of a total of 1873 monitored hours we were able to record lactate/pyruvate ratios higher than 30 in 832 hours (44 %). Of those 832 hours during which lactate/pyruvate ratios were higher than 30, ICP was higher than 20 in 193 hours (23 %). Out of 219 hours of monitoring, in which ICP was higher than 20, a simultaneously increased L/P ratio higher than 30 was recorded in 193 hours (88 %). L/P ratio values above 30 were associated with decreased CPP values (p = 0.04), but not with increased ICP values (p = 0.79). CONCLUSION: Intracranial hypertension coincides with energetic imbalance in approximately one quarter of cases. This points to the shortcomings of the most common form of neuromonitoring in SAH patients - ICP monitoring. This method may not be reliable enough in detecting hypoxic damage, which is the major cause of morbidity and mortality in SAH patients (Fig. 5, Ref. 11).

Anterior trans-frontal endoscopic management of colloid cyst: an effective, safe, and elegant way of treatment. Case series and technical note from a multicenter prospective study.

Different management options are available for the treatment of colloid cysts. Goals of those procedures are to achieve a complete resection avoiding potential long-term recurrence along with CSF pathways restoration with minimal morbidity and mortality. The two main surgical options are endoscopic resection or direct removal by either transfrontal or transcallosal approach. The efficacy of endoscopic technique to achieve gross total colloid cyst excision has been well documented. In the present study, authors describe a series of 29 patients who underwent surgery by a variation of the standard worldwide implemented endoscopic technique. Using a more anterior approach, it is easier to reach the roof of the cyst, its possible adherences with the tela choroidea, plexus, and the internal cerebral veins. The described approach has shown to be safe, quick, and very effective with a total cyst removal rate of 86.2%.

[The impact of early cranioplasty on cerebral blood flow and its correlation with neurological and cognitive outcome. Prospective multi-centre study on 24 patients]. / Impact de la cranioplastie sur l'hémodynamique cérébrale comme facteur pronostic de l'amélioration clinique chez les patients craniectomisés pour traumatisme crânien grave.

INTRODUCTION: Cranioplasty after decompressive craniectomy in patients suffering from severe head injury often leads to a functional improvement although, to date, the pathophysiology of this phenomenon remains unclear. A few hypotheses have been proposed. The impact of cranioplasty on cerebral perfusion could be one explanation. We have evaluated the impact of cranioplasty on the functional status of patients undergoing decompressive craniectomy for severe head injury with its influence on cerebral perfusion. MATERIALS AND METHODS: Twenty-four patients undergoing craniectomy for severe head injury were included in this multi-centric and prospective study. All of them had a cranioplasty within 12 weeks following decompressive craniectomy. A clinical and radiological evaluation was performed prior to and after cranioplasty. Neurological and cognitive evaluation was performed with the Glasgow Outcome Score (GOS), the Frontal Assessment Battery (FAB) and the Mini Mental State Examination (MMSE). Radiological evaluation was performed by perfusion CT scan and transcranial Doppler. RESULTS: A statistically significant neurological and cognitive improvement was observed in 92% of patients at 6 months follow-up (F-U). Brain perfusion was improved at 6 weeks F-U, predominantly in the affected hemisphere. Systolic and diastolic blood velocity flow were improved in both middle cerebral arteries. CONCLUSION: Cranioplasty after decompressive craniectomy for patients suffering from severe head injury probably improves the functional outcome of these patients, thanks to a global improvement of cerebral perfusion.

Neuroendoscopic management of posterior third ventricle and pineal region tumors: technique, limitation, and possible complication avoidance.

The endoscopic approach has gained an increased popularity in recent years for the biopsy and, in selected cases, the removal of tumors of the posterior third ventricle and pineal region. The authors report their experience on a series of 20 patients discussing also the technical limitations and complication avoidance. This is a prospective study of 20 patients with posterior third ventricle and pineal region tumors surgically managed by endoscopic biopsy and/or excision and simultaneous third ventriculostomy. The removal of the lesion could be achieved in 12 cases whereas in 8, only a biopsy could be performed. A histological diagnosis could be obtained in all cases. No delayed third ventricular stoma failures were recorded in any patient at the latest follow-up (mean follow-up, 39 months). Severe postoperative complications were recorded in 2 out of 12 cases of tumor removal attempt and in zero out of eight cases of biopsy. A delayed (3 weeks) postoperative mortality occurred in a patient harboring a GBM that developed an intratumoral hematoma 48 h postoperatively, one patient was in a vegetative state. Transient postoperative complications included: nausea and vomiting (five cases) and diplopia (two cases). One patient developed a bilateral ophthalmoplegia that recovered within 6 months due to residual tumor hemorrhage. Higher rate of complications was found in the case of vascularized and/or larger lesions. Endoscopic management of posterior third ventricle lesions may represent an effective option. However, though biopsies remain often a safe procedure, tumor excision should be limited to highly selected cases (cystic, poorly vascularized, and/or smaller than 2.5-cm lesions).

Skull bone flap fixation - reliability and efficacy of a new grip-like titanium device (Skull Grip) versus traditional sutures: a clinical randomized trial.

BACKGROUND: After completing a craniotomy, it is important to replace the removed bone flap in its natural position in order to guarantee brain protection as well as improve cosmesis. A skull defect can expose the brain to accidental damage, and in cases of larger defects it may also cause the patients psychosocial problems. The ideal fixation device should provide reliable attachment of the flap to the skull and promote fast bony healing to avoid possible pseudo-arthrosis and/or osteolytic changes. MATERIALS AND METHODS: This is a pilot randomized clinical trial on a series of 16 patients undergoing different craniotomies for benign brain lesions in which the bone flaps were replaced using traditional sutures (Prolene 0.0) in 8 cases and with a new skull fixation device (Skull Grip) in the other 8 (randomly allocated). All patients underwent CT scans of the head with 3D reconstruction at day 1 and day 90 postoperatively to evaluate bone flap position and fusion. These scans were independently reviewed by a neuroradiologist. Cosmesis was also evaluated clinically by the surgeon and radiologically by the neuroradiologist in the 2 patient groups. RESULTS: The new "Skull Grip" device has shown stronger fixation qualities with optimal bone flap fusion and increased cosmetic healing features vs. traditional sutures. CONCLUSION: The "Skull Grip" has shown to be a reliable, effective and stronger bone flap fixation device when compared to traditional sutures.

The use of optical coherence tomography in chiasmal compression.

The objective of this prospective study is to explore the benefits of optical coherence tomography (OCT) in cases of optic chiasm (OC) compression by measuring the thickness of the Retinal Nerve Fiber Layer (RNFL) and the Ganglion Cell Layer (GCL). MATERIAL AND METHODS: 16 patients (32 eyes) with chiasmal compression were included in the study. They presented no other pathology of the visual pathway or of the eye globe. The second inclusion criterion was a subsequent indication of decompressive surgery, either by transcranial or transnasal approach. Measurements of visual acuity, visual field, RNFL and GCL were performed once preoperatively and three times postoperatively (one week, 3 and 6 months postoperatively). The observed peripapillary and perifoveal regions were divided into quadrants. The degree (grade 0-5) of chiasmal compression was determined on preoperative brain MRI (magnetic resonance imaging). In need of some data analysis, participants were split into a group with no or minimal (grade 0-1) and with substantial pressure (grade 2-4) on OC. RESULTS: The median global peripapillary RNFL was 87 μm, the perifoveal nasal GCL 41,2 µm and the temporal 44,2 µm. There was a pronounced preoperative RNFL thinning in nasal (63,5 μm) and temporal (65 μm) quadrant, in comparison to the age-matched normative database for RNFL thickness in the OCT protocol. There is a statistically important connection between bitemporal hemianopia and RNFL, resp. GCL. Larger perimetric outages is related to important OC compression, seen on MRI. CONCLUSION: There exists a correlation between the thickness of the peripapillary RNFL, resp. perifoveal GCL, and visual field defects in chiasmal compression. Thinner preoperative RNFL does not present a statistically important limiting factor for better functional outcomes after surgical decompression. Horizontal asymmetry of perifoveal GCL is an indicator of compressive ophthalmopathy. The grade of preoperative OC compression presents another important prognostic factor.